Valve stem oil deflector

ABSTRACT

AN OIL DEFLECTOR ADAPTED TO BE MOUNTED ON THE STEM OF A VALVE OF AN INTERNAL COMBUSTION ENGINE COMPRISES A GENERALLY CUP-SHAPED MOLDED THERFMOPLASTIC MEMBER HAVING A RADIALLY EXTENDING WALL SECTION AND AN INTEGRAL AXIALLY EXTENDING RIBBED SKIRT SECTION, THE WALL SECTION INCLUDING AN INTERIORLY EXTENDING THICKNED NECK SECTION DEFINING A TAPERED BORE ADAPTED TO RECEIVE THE VALVE STEM THEREWITHIN.

P 20, 1971 J. A. BUSH 3,605,706

VALVE STEM OIL DEFLECTOR Filed Dec. 12, 1969 INVETOR.

United States Patent Ofice 3,605,706 Patented Sept. 20, 1971 3,605,706 VALVE STEM OIL DEFLECTOR Jack A. Bush, Birmingham, Mich., assignor to Microdot Inc., New York, N.Y. Filed Dec. 12, 1969, Ser. No. 884,554 Int. Cl. F011 3/06; F16j /32, 9/04 US. Cl. 12390.37 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Valve stem seals for internal combustion engines are subjected to repeated heating and cooling cycles. These, along with resulting material shrinkage that may occur, provide a high internal stress condition that may result in fracture.

BRIEF SUMMARY OF THE INVENTION It is the purpose of the invention to provide a high strength, fracture resistant, inexpensively manufactured, easily assembled, molded thermoplastic valve stem oil deflector for internal combustion engines.

The invention accomplishes this purpose by means of a cup-shaped member with a tapered inside neck that grips and seals on the valve stem. The neck is thicker than the end wall and skirt of the cup and the knit line strength and fracture strength are further improved by longitudinal ribs extending on the inside of the cup from the bottom of the skirt for the full length of the skirt and wall to the neck.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary cross sectional view of a portion of a conventional internal combustion engine having a one-piece, molded oil deflector in accordance with a preferred embodiment of the present invention in operative association therewith;

FIG. 2 is an enlarged cross sectional view taken sub stantially along the line 2-2 of FIG. 1; and

FIG. 3 is a cross section along the line 3-3- of FIG. 2.

DESCRIPTION OF THE INVENTION Referring now to the drawings, a conventional internal combustion engine 10 of the overhead valve type is shown as comprising a head 12 having a valve lifter or rocker arrn cover 14 mounted thereon and secured thereto in any known or suitable manner. The engine head 12 is provided with a passage 16 communicating with a combustion chamber fragmentarily shown herein at I18, the lower end of the passage 16 defining an annular valve seat 20. The valve seat 20 is adapted to be selectively opened and closed by means of a conventional valve member 22 having a valve head section 24 adapted to sealingly engage the valve seat 20'. The valve member 22 has a valve stem section 26 reciprocable in a valve guide 28 supported within a bore 30 defined by the engine head 12.

The upper end of the valve stem 26 is surrounded by a helical compression spring 32 which is supported at the lower end thereof by an annular bushing or spring locater 34 coaxially located about the valve guide 28 and bearing against a fixed portion 35 of the engine head 12. The upper end of the spring 32 abuts against a spring retainer member 36 held in place by a conventional valve spring retainer lock 38 that is partially disposed within an annular groove 40 adjacent the upper end of the valve stem 26. One end of a rocker arm, generally designated 42, bears against the upper end of the valve stem 26 and is adapted to effect reciprocal movement of the valve member 22 in a manner well known in the art.

In accordance with the principles of the present invention, the valve member 22 is provided with a cupshaped valve stem oil deflector, best illustrated in FIGS. 2-3 and generally designated by the numeral 44. The deflector 44 is made of a molded resinous thermoplastic material which is relatively stiff, non-collapsible, and resistant to heat up to at least approximately 350 F. without losing its form, shape, or substantial strength. One preferable material is glass filled nylon which has been found to not only have the requisite heat resistant characteristics, but is also available at an economical price. It will be apparent that different types of equivalent materials could be used in fabricating the deflector 44 of the present invention and that the material should be one that does not permit harmful internal dimensional expansion due to heating and cooling cycles.

In accordance with the present invention, the cup 44 is one piece or monolithic and comprises an end wall section that is joined by a radius to a skirt section 48 which flares outwardly a slight amount toward the bottom end thereof. The end wall 46 also is joined to an interiorly extending neck section 50 by a fillet portion 52. The neck is inside of and coaxial with the skirt 48. It is formed with a central aperture 54 through which the valve stem 26 extends and which is uniformly tapered radially inwardly toward the upper end of the deflector 44, with the result that the diameter of the lower end of the bore 54 is somewhat larger than the diameter of the upper end. In a preferred embodiment, the bore 54 is tapered on an angle of approximately /2 inch per foot. The size (diameter) of the aperture 54 is selected so that the lower end is slightly larger than the diameter of the valve stem 26, while the upper end is somewhat smaller in diameter than the valve stem 26. Also, the lower end of the bore 54 is flared radially outwardly a slight amount, as seen at 56. The tapered configuration of the bore 54, together with the outwardly flared portion 56, enables the oil deflector 44 to be easily assembled onto the upper end of the valve stem 26 due to the relatively larger size of the opening at the lower end of the bore 54 with respect to the size of the valve stem 26. Since the bore 54 decreases in size toward the upper end of the deflector 44, the inner periphery of the bore 54 will tightly grip and sealingly engage the outer periphery of the valve stem 26 as the deflector 44 is assembled thereon even though there may be some dimensional variation in the members 44 or 22.

The skirt 48 and the outer annular portion of end wall 46 are of uniform thickness except for four longitudinal, inside ribs 58 which extend the full length of the skirt 48 and into the fillet portion 52 so that the top end of each rib is integral with the neck 50 and wall 46 as seen in the right of FIG. 2. The ribs are preferably sized and shaped as shown in FIG. 3. One of the ribs is at the injection point during molding which allows for quicker access of the plastic material and gives a flow channel to the neck space. The rib opposite the injection point and the other ribs give a heavier wall to add to the strength of the knit line, thereby improving fracture strength. In molding the gate is located at point 60 (FIG. 1) on the bottom end and outer circumference of the cup.

The neck 50 is somewhat thicker than the wall 46 and skirt 48 which together with the ribs give a high gripping or holding power without the use of a spring or clamp 3 and also provides maximum mass at the greatest point of stress to give a strong knit line. Since the neck is inside the skirt 48 a minimum length cup is achieved.

The oil deflector 44 is assembled upon the valve stem 26 prior to the compression spring 32 and its associated parts being assembled thereon, but after placement of the bushing or spring locater 34 about the valve stem guide 28. The deflector 44 is initially disposed relatively adjacent to the guide 28, and the first time the valve 22 is moved to an open position (downwardly), the bottom of neck 50 abuts the upper end of the valve guide 28 so that the cup is forced axially along the valve stem 26 to a predetermined position, which position the deflector 44 will permanently assume on the valve stem 26 during subsequent operation of the engine 10. In this position, the bottom of the skirt 48 is somewhat below the top of the guide 28 as seen in FIG. 2.

In operation, the valve stem oil deflector 44 deflects the lubricating oil and spray within the valve cover 14 away from the upper end of the passage 30, thereby preventing it from entering into the combustion chamber 18 of the engine 10. Because of the tight sealing engagement between the outer periphery of the valve stem 26 and the periphery of the bore 54, oil cannot flow downwardly along the valve member 22 between the deflector 44 and the valve stem 26.

Thus, it will be seen from the foregoing description that the present invention provides a monolithic, high strength, properly shape, molded oil deflector construction which may be economically manufactured and easily assembled on the associated valves of many types of internal combustion engines. The thickened radiused neck 50 and the ribs 58 provide a reservoir of strength to resist fracture due to shrinking of the already tight aperture 54 as a result of repeated heating and cooling cycles.

Variations from the specific construction shown may be made without departing from the spirit and scope of the invention.

I claim:

1. An injection molded oil deflector type seal for attachment to the valve stem of an internal combustion engine or the like comprising an injection molded monolithic non-metallic cup having a side wall and an end wall, said end wall including an opening for receiving a valve stem whereby said cup is mounted on the valve stem, said side wall and opening being coaxial, said end wall having a neck portion providing said opening and extending from the end wall to the inside of the cup and of greater thickness than the end wall, said opening being tapered with the smaller portion thereof at the outer face of the end wall, said cup having a smooth outer side Wall surface and having angularly spaced ribs on the inside of the side wall and the end wall, said ribs thicker than said walls and having straight portions extending the full lengths of the side wall and transverse portions extending across the end wall and merging with said neck to provide for reinforcement of the side wall and neck.

2. A deflector as set forth in claim 1 wherein said deflector has a molding injection joint located at one of said ribs.

3. A deflector as set forth in claim 1 including a molding gate point on the outer edge of the side wall remote from said end wall.

References Cited UNITED STATES PATENTS 2,876,759 3/1959 Duesenberg 123-188(P) 3,369,819 2/1968 Soo 277-178 3,451,700 6/1969 Smith 277-2l2X 3,492,982 2/ 1970 Norris 277-33 AL LAWRENCE SMITH, Primary Examiner U.S. Cl. X.R. 27733, 152, 212 

